Venn diagram showing the number of epitope association rules involving each gene. Out of the 484 unique epitope associations, there were 9 associations in which epitopes from the Gag gene only (shown in red) were involved and 94 from the Pol gene only(blue). There was no association in which epitopes from solely Nef (green) were involved. There were 329 associations in which epitopes from Gag and Pol took part, whereas in 26 associations epitopes were only from the Nef and Pol genes, and in 3 associations epitopes were only from the Gag and Nef genes. There were 23 associations in which epitopes from all three genes were involved.